The present invention is directed to a method for controlling a printing material processing machine and to a device for controlling the same.
To control or regulate the time sequence of operations in printing material processing machines, numerous procedures are known, which use software to simulate the printing substrates to be transported through the printing material processing machine. This means that when a printing material, i.e. a printing substrate, preferably a paper sheet, is transported through a printing material processing machine, in particular a printing press, speed and position sensors in the printing press are used to store the particular position and corresponding speed of a specific sheet at a specific point in time in the printing press, in a memory device. Such a procedure is known, for example, from German Patent Application No. DE 42 29 645 A1. In this procedure, when working with a running printing press having a digital position-measuring system, the position of a printing substrate within the printing press is measured in relation to a reference location. In addition, a digital speed sensor is used to continually record the transport speed of the printing substrate along its transport path, the printing speed of the printing press, or the speed of specific drive system components of the printing press. In the process, the data of the position-measuring system and of the speed sensor are continuously fed to a computer, which constitutes part of the machine control of the printing press. Moreover, the computer of the machine control receives other signals from transmitters and sensors mounted on various components of the printing press. On the basis of the thus discretized printing substrate, it is assured that the processing steps for a printing substrate always take place precisely when the printing substrate is in the position required for the processing step. Such a method eliminates the influences of dead and delay times associated with every actuator or switching element of a printing press and, in this way, improves the accuracy of a printing press.
A system for simulating the conveyance of a paper sheet through a copying machine is known from European Patent Application No. 0 809 156 A1. In this system, on the basis of data obtained via sensors from the real transport system of a copying machine, a virtual sheet-transport system is simulated. In this way, the proper functioning of the sheet transport through the copying machine can be checked. The virtual sheet in such a simulation system is represented, in this context, by the opposite ends of a paper sheet and the distance therebetween, thus the length of the sheet. The beginning, end and length of the paper sheet are then stored as data, always as a predetermined unit transported through the virtual sheet-transport system of the copying machine. In this manner, the position of the paper sheet in the copying machine can be determined at any point in time.
An object of the present invention is to devise a method and a device for implementing a method, which enable individual sheets, passing through a printing material processing machine, to be marked in such a way that they run through specific process sequences at specific positions of the printing material processing machine. It is intended, in the process, to especially avoid any visible marking of the sheets, such as marks produced by punching.
The present invention provides a method for controlling a printing material processing machine (1, 2, 3), which has at least one processing unit in which the positional and speed data of a printing substrate to be transported through the printing material processing machine are recorded, where, on the basis of the recorded positional and speed data, the instantaneous position of the printing substrate is calculated and stored in memory means of the processing unit. In addition to the instantaneous position of a printing substrate to be transported through the printing material processing machine, additional command data are stored in the memory means.
The method according to the present invention provides the considerable advantage that information or commands associated with a specific printing substrate, are transported in a time-synchronous or angle-synchronous manner through a printing material processing machine. In conventional printing material processing machines, printing substrates, in particular paper sheets, whose processing deviates from the normal processing, are physically marked. This means that either a mark is imprinted on the paper sheet, or a hole is punched in, thereby signaling to the particular processing station of a printing press that this punched sheet is to undergo a particular processing step. This can mean, for example, pulling out a sample sheet. The disadvantage of marking a paper sheet in this way is, of course, that the sheet is physically altered, i.e., it has a visible mark that has a disruptive effect. The method according to the present invention has found an elegant way to circumvent this problem since the sheet is no longer physically marked, but is virtually marked. For this reason, the control of the printing material processing machine has a special program which virtually simulates all of the paper sheets to be transported through the printing material processing machine. Using such a technology, one may access the instantaneous position of any one paper sheet in the printing press at any given point in time. Besides the momentary situation of a paper sheet in the printing material processing machine, the method according to the present invention additionally provides for storing other data and information. The data may thus include a virtual marking or a specific command. If, at this point, the real and the virtual paper sheet, which, of course, are always transported simultaneously through the machine, arrive at the station where the additionally stored command or the marking are to trigger a process, then this process is executed at the station. However, the real paper sheet subjected to this process is not distinguished at all from the other paper sheets, since no physical marking had been applied. Outwardly, therefore, the paper sheet is completely intact and undamaged. Another significant advantage of the method is that the need is eliminated for sensors for detecting a marking or any other change in the paper sheet at the stations of the printing material processing machine which carry out the process. The special processing step is thus triggered at the station of the printing material processing machine exclusively on the basis of the data pertaining to the sheet in question stored in the machine control.
Instead of storing the speed and positional data, as well as the additional command data of a paper sheet to be transported through the printing material processing machine in accordance with the present invention as a function of the particular point in time, it is also possible to store the particular corresponding angular position. This procedure is preferred in printing presses, since they require an ongoing counting of the machine angles, which makes these angles useful as a reference basis. The technique of continually counting the machine angle is conditional upon angles which increase by 360 degrees with every rotation.
To determine the speed and the positional data of a paper sheet to be transported through the printing material processing machine, the incremental encoders of the individually rotating cylinders or the machine tachometer, already present in a printing material processing machine, are advantageously operated as data suppliers. This makes it possible to economize on additional sensors, which would otherwise be needed to supply the mentioned data.
The present invention also provides a device for controlling a printing material processing machine (1, 2, 3), which has at least one processing unit for recording positional and speed data of a printing substrate to be transported through the printing material processing machine, and which has memory means in the processing unit for storing the instantaneous position of the corresponding printing substrate calculated on the basis of the recorded positional and speed data. The memory means are designed to store assigned command data, in addition to the instantaneous position of a printing substrate to be transported through the printing material processing machine.